Andres,
I was talking this over with Jeff on the plane, and we wanted to be
clear on your goals here: are you looking to eliminate the *write* cost
of freezing, or just the *read* cost of re-reading already frozen pages?
If just the latter, what about just adding a bit to the visibility map
to indicate that the page is frozen? That seems simpler than what
you're proposing.
--
Josh Berkus
PostgreSQL Experts Inc.
http://pgexperts.com